The subject matter disclosed herein relates to turbines and, more particularly, to a drum rotor retrofit of a steam turbine.
Some power plant systems, for example certain simple-cycle and combined-cycle power plant systems, employ turbines (e.g., steam turbines) in their design and operation. These steam turbines define a steam path which is used to channel and generate power from steam being conveyed through the power plant system. Some of these steam turbines include a wheel and diaphragm section as a portion of the steam path. The wheel and diaphragm section includes a rotor, and sets of buckets, wheels, blades, and nozzles which are configured to define a number of stages within an outer shell of the steam turbine. These stages contribute to the efficiency and reaction of the steam turbine. However, the wheel and diaphragm sections of some steam turbines may have mechanical limitations, non-optimized rotors and steam paths, small rotor diameters, poor stiffness, and/or a high dynamic response. These limitations and inefficiencies may cause rubbing within the turbine and decreased efficiency of the power plant system. Some power plant systems completely replace these wheel and diaphragm sections with drum rotor sections which may have increased stiffness and efficiency. However, complete replacement may necessitate a significant amount of down time, retooling and materials; requiring that all components, including the outer shell of the previous wheel and diaphragm section be replaced.